Lakes and climate change - a paleoecological perspective

Abstract

The physical, chemical, and biological characteristics of lakes are often closely associated with climate, although the linkages may be indirect and complex. Warmer temperatures and other climatic factors affect lakes in different ways, depending in part on limnological characteristics, as well as regional and site-specific differences of each lake. Nonetheless, general patterns can often be discerned. For example, many lakes are changing with respect to the amount and duration of ice cover, the length (if any) of thermal stratification, as well as changes in the ratio of evaporation and precipitation. In some cases, critical ecological thresholds are being crossed in response to new climate regimes, particularly in regions with strong seasonality. Although long-term monitoring data are rarely available, sediment that accumulates at the bottom of lakes contains an important archive of past conditions. Physical, chemical, and biological remains in sediments inform paleolimnologists, who reconstruct long-term trends, many of which can be linked to climate. Such studies have provided key evidence in demonstrating the effects of natural versus human-induced climatic change.